Answer:
Contractile ring.
Step-by-step explanation:
Animal cell cleavage furrow formation is caused by a ring of actin microfilaments called the contractile ring, which forms during early anaphase. Myosin is present in the region of the contractile ring as concentrated microfilaments and actin filaments are predominant in this region.
Hope this helps. Don't know that much about it but I'm also figuring this out.